Conventionally, in case of carrying out detection of a very small amount of a substance, various specimen detection devices with which such a substance can be detected by applying a physical phenomenon of the substance have been used.
One of such specimen detection devices is an SPFS device with which analyte detection can be carried out with a high precision on the basis of a principle of a surface plasmon-field enhanced fluorescence spectroscopy (SPFS) applying the surface plasmon resonance phenomenon.
The surface plasmon-field enhanced fluorescence spectroscopy (SPFS) is a method in which the evanescent wave generated by incoming of excitation light under the attenuated total reflection (ATR; attenuated total reflectance) conditions is resonated with surface plasmons on the surface of a metal thin film, and thereby, localized electric field, which is enhanced several tens to several hundreds of times, can be formed on the surface of the metal thin film; a fluorescent substance with which a captured analyte is conjugated (labeled) is set in this enhanced localized electric field; the fluorescence of the fluorescent substance is efficiently excited; and, by observing this fluorescence, a very slight amount or a very low concentration of an analyte is detected.